1. Field of the Invention
This invention relates generally to disposable, flexible, self-sealing storage bags and, more particularly, to an improved interlocking feature for disposable, self-sealing storage bags that facilitates the convenient evacuation of air therefrom, capable of creating a vacuum therein, and/or the maintenance of a true, airtight seal to keep air from leaving or entering the bag. The invention further relates to the manufacturing process for the inventive storage bag.
2. Description of Related Art
Self-sealing, disposable, plastic film bags are well known in the prior art. Self-sealing bags are flexible and disposable and incorporate interlocking strips which extend across the entire open end of the bag. The interlocking strips include mateable male and female, or tongue and groove portions which interlock to close the open end of the bag. Conventional interlocking bags include those sold under the trademark Ziplock.RTM.. Once contents are placed in the storage bag, the male and female strips are oriented, engaged, and pressed shut by applying continuous compression across the strips with the fingers or a slide mechanism. Conventional self-sealing bags, however, are not designed for conveniently evacuating air from the bag or for maintaining an airtight seal.
Self-sealing bags are primarily purchased in the consumer market for storing perishable foods. The bags are used to temporarily store food, such as leftovers or sandwiches, or to place food, such as meats, in the freezer over a long period of time. Despite the convenience and success of self-sealing bags, food can still go stale or suffer freezer burn. This is because conventional self-sealing storage bags do not offer structure for evacuating air or making a true airtight seal. To evacuate air from inside the bag, users try to keep a segment of the bag open while pressing down on the bag to force air out. This process fails to remove all the air and is a crude, inconvenient way to evacuate air. The conventional self-sealing bags also fail to provide true airtight seals. This is because they do not have structure, such as rubber gaskets, for preventing air from passing between the interlocking portions. Tests have been conducted which show that a self-sealing bag that is filled with air will deflate over a period of time. Likewise, air can enter the bag between the interlocking portions. Since air cannot be kept out of the bag or evacuated, frozen food experiences freezer burn and non-frozen food becomes stale. If self-sealing bags were constructed in a way that facilitated the evacuation of air and/or the creation of a truly airtight seal, such a bag would keep food fresh indefinitely and would be well received.
Self-sealing bags could also be used for storing and discarding biohazardous waste in the medical and dental fields if an airtight seal was achievable. Biohazardous waste includes tissue specimens, intravenous bags, rubber gloves, urine samples, laboratory rats, and other medical trash. Biohazardous waste comprises any solid or liquid product that could potentially transmit airborne illnesses, communicable illnesses, and infections to the public. The proper disposal of biohazardous waste has become increasingly important, especially in light of diseases, like AIDS, and problems with medical waste washing up on beaches in Florida, New Jersey, New York, and Connecticut. In fact, medical waste has historically been deposited in regular trash receptacles that are directly exposed to ambient. Because of the inherent, obvious dangers of biohazardous waste emissions and the ongoing, improper handling of said waste, the Environmental Protection Agency (EPA) is requiring all companies that handle medical waste to install equipment to cut down on dangerous emissions. An airtight, self-sealing, disposable bag would provide a simple, inexpensive solution for preventing the dangerous emission of biohazardous waste prior to its delivery to incinerators.
Several attempts have been made in the prior art to provide flexible, disposable, self-sealing bags which are capable of having air evacuated therefrom. However, none of these references has addressed or adequately solved the above-noted issues. One of the main problems associated with providing an airtight, self-sealing bag that evacuates air relates to manufacturing. That is, current flexible plastic bags are extruded at a high rate of speed, making it difficult, if not impossible, to alter the structure of the bag without affecting production. The prior art has failed to proffer a flexible bag that can be easily adapted to existing manufacturing machinery and procedures.
Known evacuation assemblies comprise separate structures which must be molded into the bag or include permanent conduit structures. Existing self-sealing bags further have failed to provide any gasket structure for effectuating a true, airtight seal. For instance, U.S. Pat. No. 5,240,112, issued to Neuberger, comprises a thin, flexible plastic bag having a conventional main zipper closure at its upper end and a stem with a pinched valve protruding outward from the lower end. U.S. Pat. No. 5,544,752, issued to Cox, teaches an evacuable storage bag that includes a permanent, exterior suction conduit that is designed to break off after use and has cooperative sealing strips therein for sealing the conduit once air has been evacuated. The '112 and '752 Patents cannot be adapted to existing extrusion manufacturing techniques, do not teach an evacuation opening that is contiguous with the main opening, and cannot hold an airtight seal. U.S. Pat. No. 4,923,701, issued to Van Erden, comprises a zippered cook-in-the-bag pouch which is designed to withstand, without deterioration, maximum cooking heat. The '701 Patent does not address or teach the evacuation of air or a self-sealing strip that provides a true airtight seal. U.S. Pat. No. 3,980,226, issued to Franz, comprises an evacuable bag having a permanently affixed evacuating tube with a threaded cap and an open end which is tied shut. The '226 Patent does not provide a true airtight seal and is incompatible for existing extrusion manufacturing. U.S. Pat. No. 5,142,970, issued to Erkenbrack, comprises an apparatus for storing matter out of contact with gas and is not pertinent to the particular problems discussed herein. The '970 Patent is not adaptable to existing extrusion manufacturing and does not provide a true airtight seal. U.S. Pat. No. 5,339,959, issued to Cornwell, discloses a disposable medical waste bag having an open top end which is twisted shut and a valve for connecting a vacuum. The '959 Patent is not self-sealing and does not provide an airtight seal. U.S. Pat. No. 5,494,165, issued to Detrick, comprises a rigid container for holding articles to be vacuum-packed comprising an open end, a lid which makes airtight engagement with the open end, and a tube that projects through the lid in an airtight fit and communicates with the interior of the container for evacuating air. The '165 Patent does not contemplate a self-sealing, flexible, disposable bag.
The foregoing devices fail to teach a self-sealing, disposable, flexible bag capable of having air evacuated therefrom, and providing a true airtight seal for keeping air from entering or exiting the bag. As the prior art fails to teach an evacuable and/or an airtight bag for keeping food fresh in one use, or for retaining biohazardous waste in an airtight, disposable package in another use, there exists a need for a self-sealing, disposable storage bag that is capable of evacuating air and/or maintaining a true airtight seal.